Well let's see.
My friend drives an 03 6speed Base model with roughly 130k miles, its stock except for an intake, springs and shocks. He's a pretty spirited driver and has only replaced the clutch once so far, I've driven his car recently and it feels no different than a later model Z33 with lower miles.
If the 370 really is a vastly improved piece of work above the 350, then your car should stay pretty crisp for the years to come. I know mine has.
